New coffee (Coffea arabica) genotypes derived from Coffea canephora exhibiting high levels of resistance to leaf rust and Ceratocystis canker

Abstract

The purpose of this study was to evaluate the resistance to coffee leaf rust (CLR) caused by Hemileia vastatrix and to Ceratocystis canker (Cc) in coffee genotypes derived from crosses of Coffea arabica var. Caturra with accessions of C. canephora backcrossed to Caturra. Twenty-three F3BC1 progenies including C. arabica var. Caturra and var. Colombia as controls were established in a field experiment. CLR evaluations were made during five years of natural infection, using an incidence rating scale. For Cc, artificial stem inoculations were made with an isolate of Ceratocystis colombiana and the results were assessed after one year. The selection process also included agronomic aspects such as plant height, canopy diameter, number of branch pairs, yield and grain characteristics. Twenty progenies showed >70% of rust resistance. Twelve progenies exhibited >80% of Cc resistance, while no resistance was observed in either of the controls. Only three progenies performed well for all criteria, including resistance to both pathogens and agronomic characteristics.